Electrical plug connector systems in which electrical contacts or contact elements are installed, together with the electrical leads disposed thereon, in a wiring harness plug connector, are known from the existing art. Often the contact element having the electrical lead crimped thereonto is guided into a preinstalled wiring harness plug connector. In order to enable sealing of the electrical contacts or contact elements and of the electrical leads with respect to fluid media (gases or liquids) from an external environment of the wiring harness connector, the electrical lead is often passed through a mat-type seal before the electrical contact element, together with its electrical lead fastened thereon, is introduced into the contact carrier. In another embodiment the seal can be brought about by the fact that the electrical contact or contact element is embodied using a so-called single-wire seal. A single-wire seal of this kind can be disposed, for example, at the crimp connection between the electrical contact element and the electrical lead, and then seals the electrical contact element in the contact carrier with respect to the external environment of the wiring harness plug connector.
A wiring harness plug connector having a mat-type seal is described in German Patent Application NO. DE 10 2011 080 347 A1.